I was sure about one thing -- I didn't want any f***ing barrels." Director Andrew Dominik is referring to that staple of the classic western, the large beer or whiskey barrel.

They are usually dotted around the sets of practically every cowboy film you can think of and which tend to become exploding projectiles during the inevitable saloon brawl.

You'll find none of that sort of nonsense in Dominik's new film, because in many ways The Assassination Of Jesse James By The Coward Robert Ford is an anti-western that debunks some of the more cherished myths that have grown up around the supposed heroes of the American west. Brad Pitt stars as the legendary Missouri outlaw Jesse James and Casey Affleck plays Ford, a callow fan who would become his hero's executioner. And from its opening scenes, this extraordinary looking picture proclaims its distinction from almost every other western you've seen.

The film is based on a novel by Ron Hansen that Dominik adapted, and from the very start the New Zealander had a strong vision of what the film would look like. "As soon as you start doing any visual research," he tells me, "you realise that America in that period looked so Victorian, I mean the photos looked like something out of Oliver Twist. And the other thing is that the story is set mainly in St Joseph and Kansas City, which were big, rapidly-expanding cities at that period, so it wasn't like the old frontier. Nobody wore cowboy hats, they wore homburgs and bowlers. So the idea of making a Dickensian western was really appealing."

And Dominik's Dickensian western would not, as we have noted, be featuring any barrels. "When we went to western Canada, where we shot the film, they had this big prop house which was kind of a western prop house, and when we walked in, half the place was lined with these barrels. And I was like, oh no..."

In fact, Dominik and his cinematographer Roger Deakins created a film whose look completely subverts the conventions of the genre, with stylishly-muted landscapes, autumnal colours, stark Victorian interiors and lingering shots of a dying breed of American outlaws. And at its centre is the charismatic but decidedly unheroic figure of James himself.

The film deals with the last year of James' life, by which stage, as Dominik puts it, "he was clearly not a happy camper". And the New Zealander (whose previous credits include the critically-acclaimed prison drama Chopper) reveals the extent to which he has immersed himself in the period as he describes the reasons for his central character's imbalance.

"These were bad boys. Jesse and his brother Frank rode with Bloody Bill Anderson during the Civil War and that guy was just bananas. It was like ethnic cleansing what went on in Missouri during that war; they would shoot neighbours who were Union sympathisers. And Bloody Bill used to send Jesse into Union bivouacs in the middle of the night with a tanning knife -- he was just 16 at that point, but apparently had a real talent for killing people. I don't think he ever recovered from those experiences."

The idea of Jesse the romantic outlaw was largely the invention of a hack journalist called John Newman Edwards, with whom James would sometimes collaborate after robberies and raids "to decide how they were going to portray it in the press". But in reality, Jesse was a volatile killer who shot dead at least 17 people during his 12-year outlaw spree, often on the flimsiest of pretexts. And Brad Pitt's shifty-eyed, jumpy and paranoid portrayal of him reflects this.

Dominik believes Pitt was the right choice for James for a number of reasons. "It's very difficult to cast a movie star as an ordinary person, and Brad can really only play extraordinary people. The other thing about Brad is he's someone you never really feel like you know on screen. I don't think, in any movie of his I've ever seen, I've identified with him, in the sense that he retains that sort of essential mystery like those old-time movie stars where you don't really feel like you know him. And that seemed to be a really good thing for Jesse."

The central relationship in Dominik's deconstruction of a western fable is the one between James and Bob Ford and the film even goes as far as to suggest that Jesse almost picked out and groomed Ford as the one who would kill him.

"It certainly seems that way to me," says Dominik. "I think Jesse is obviously kind of depressed, and you see him throughout the movie struggle with the idea of protecting himself -- he's certainly allowing cracks to form around him and it seems like he's doing it consciously. He seems really indecisive about whether he wants to live or die, and the intention is that it's kind of a tale of assisted suicide, you know.

"I mean, three days before the assassination Jesse bought Robert Ford a gun, and people actually speculated at the time as to whether it was deliberate on Jesse's behalf. I think Brad always felt it was a little more opaque than that, though, and I'm not sure everybody sees it exactly that way."

In fact, Dominik remembers some "retarded reactions" to the film's climactic scene when it was initially screened to gauge audience reactions. "You'd get these people writing things down like, 'Why didn't Jesse turn around and shoot him when he could clearly see him in the mirror' and you felt that they mustn't have seen the previous two hours of the movie.

"They clearly just thought, well he's Brat Pitt, he's Jesse James, so he must be feeling good, you know. It's really clear to me within the first two minutes that Jesse's not happy, but I think some people have another movie in their head that they're expecting to see and, despite all evidence to the contrary, that's the film they see."

Given that it's in the film's title and is in any case one of the most iconic moments in the history of the American west, the movie's climactic scene will come as no surprise to viewers. But Dominik's film doesn't stop there. A meditation on celebrity -- at the time of his death James was the most famous man in America -- it deals not only with Jesse's fame but with the notoriety that came Bob Ford's way after he had shot him.

For much of Jesse's career he had been popular as well as famous, thanks mainly to the efforts of his fanciful journalistic biographer.

"But I think public opinion had turned against them towards the end," says Dominik, "so Bob was able to cash in for a brief period, until the legend rose up and swamped him."

Ford cashed in by embarking on a theatrical tour of America's industrial north east, in which he and his brother Charley re-enacted the assassination of Jesse James. And bizarre as that sounds, it was quite normal practise at the time. "It was not an uncommon thing at all, because in the east they had a hunger for everything that was in the west. So Kit Carson had a stage show, Buffalo Bill did, even Frank James took to the boards at one point.

"Bob and Charley did it for about a year, and I suppose it is pretty amazing that a person's life gets reduced down to this one thing they did, this one defining action, and then they have to relive it again and again and again on stage.

"And if you think about somebody wrestling with and trying to come to terms with something they've done, the idea of performing it every night in front on an audience is just fantastic."

There are rumours, meanwhile, that Dominik and Brad Pitt were not quite in agreement about the fine details of the final cut, but all the director will say is that's he's "happy -- I mean there are a few things I would change if I was able to do a director's cut, but you know it's pretty close to what I wanted".

The Assassination of Jesse James By The Coward Robert Ford has been talked about in terms of Oscars, but the director is not getting the champagne ready just yet.

"Obviously, we really hope we get that kind of attention," he says, "because it's good for the picture and good for everyone personally.

"But as to whether it'll go the distance, it's really hard to say. It hasn't performed brilliantly in the US box office-wise, and critical opinion over there is really split. I mean it's mainly favourable, but people either seem to absolutely love it, or absolutely hate it. Which is kind of a good thing I suppose." n

The Assassination Of Jesse James By The Coward Robert Ford opens today.